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        <td class="header">&nbsp; Snaphu Data Import</td>
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<h3>Importing results from SNAPHU processing</h3>

<h4>Important note</h4>

<p>
    It is strongly advised before executing graph for exporting data for SNAPHU processing for user to get familiar
    with general principles of doing <a href="Unwrapping.html">phase unwrapping</a>.
</p>

<h4>
    SNAPHU Data Import Graph
</h4>

<p>
    The main purpose of SNAPHU data import function is two-fold:
<ol>
    <li>
        To import results of SNAPHU processing,
    </li>
    <li>
        To construct Interferometric product that will contain unwrapped phase band, and the metadata of the source
        interferometric product.
    </li>
</ol>

<p>
    The import graph is visualized in the figure below.
</p>

<img style="" alt="" src="../images/SnaphuImportGraph_fig0.jpg"><br/>

<p>
    In the export graph, there are two readers, and one writer. <strong>Two readers</strong> are reading the phase
    product, constructed during <a href="SnaphuExportOp.html">exporting data for SNAPHU processing</a>, and other reader
    is reading imported unwrapped result of SNAPHU processing as "Generic Binary". Snaphu Import operator arranges the
    metadata and bands, and constructs the unwrapped phase product compatible for further utilization within the Toolbox. Finally,
    writer saves the product in DIMAP format.
</p>

<p>Specifically the import graph performs the following:</p>

<dl>
    <dt><strong>1-Read-Phase:</strong></dt>
    <dd>Reads the "phase-only" interferometric product constructed during Snaphu Data Export step.</dd>

    <dt><strong>2-Read-Unwrapper-Phase:</strong></dt>
    <dd>Reads the "unwrapped-phase-only" product ingested in the Toolbox using Generic Binary Readers. <b>Note</b> that
    due to restrictions of the framework currently it is not possible to chain the generic binary reader in the graph, and hence
    it is not possible to ingest unwrapped data directly into the Toolbox. This has to be done outside Snaphu Import graph.</dd>

    <dt><strong>3-SnaphuImport:</strong></dt>
    <dd>Arranges the metadata and merges the bands of the source product into a unwrapped phase product. In this step
        metadata and bands are arranged in a compatible form for further InSAR processing.
    </dd>

    <dt><strong>4-Write:</strong></dt>
    <dd>Writes "unwrapped phase product" in the standard DIMAP format.</dd>
</dl>

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